Cassini launched aboard a Titan IVB/Centaur on 15 October 1997, Cassini had been active in space for nearly 20 years, with 13 years spent orbiting Saturn, studying the planet and its system since entering orbit on 1 July 2004. The voyage to Saturn included flybys of Venus (April 1998 and June 1999), Earth (August 1999), the asteroid 2685 Masursky, and Jupiter (December 2000). Its mission ended on 15 September 2017, when Cassini flew into Saturn’s upper atmosphere and burned up at a very high temperature, in order to prevent any risk of contaminating Saturn’s moons, some of which have active environments that could potentially bear life. (At that point Cassini lacked sufficient power to leave the Saturn system so it could only be left in orbit where it might collide with a moon or be destroyed). The mission is widely perceived to have been successful beyond expectation. Cassini-Huygens has been described by NASA’s Planetary Science Division Director as a “mission of firsts”, that has revolutionized human understanding of the Saturn system, including its moons and rings, and our understanding of where life might be found in the Solar System.

Cassini‘s original mission was planned to last for four years, from June 2004 to May 2008. The mission was extended for another two years until September 2010, branded the Cassini Equinox Mission. The mission was extended a second and final time with the Cassini Solstice Mission, lasting another seven years until 15 September 2017, on which date Cassini was de-orbited by being allowed to burn up in Saturn’s upper atmosphere.

The Huygens module traveled with Cassini until its separation from the probe on 25 December 2004; it was successfully landed by parachute on Titan on January 14, 2005. It successfully returned data to Earth for around 90 minutes, using the orbiter as a relay. This was the first landing ever accomplished in the outer Solar System and the first landing on a moon other than our own. Cassini continued to study the Saturn system in the following years.

At the end of its mission, the Cassini spacecraft executed the “Grand Finale” of its mission: several risky passes through the gaps between Saturn and Saturn’s inner rings. The purpose of this phase was to maximize Cassini‘s scientific outcome before the spacecraft was destroyed. The atmospheric entry of Cassini effectively ended the mission, although data analysis and production will continue afterwards.

NASA has reported a catastrophic event is taking place in space, but scientists are still investigating what exactly has happened or happening. Mysterious flashes of X-rays beamed towards Earth before vanishing just 24 hours later, leaving scientists to investigate the source. Initial findings suggest it came from a “completely new type of cataclysmic event”. The phenomenon was captured by NASA’s Chandra X-ray Observatory, stemmed from a galaxy 10.7 billion light years away. The X-ray source, is located in the sky known as Chandra Deep Field-South (CDF-S).

Interstellar travel is the term used for hypothetical manned or unmanned travel between stars. Interstellar travel will be much more difficult than interplanetary spaceflight; the distances between the planets in the Solar System are less than 30 astronomical units (AU)—whereas the distances between stars are typically hundreds of thousands of AU, and usually expressed in light-years. Because of the vastness of those distances, interstellar travel would require either great speed, a high percentage of the speed of light, or huge travel time, lasting from decades to millennia or longer.

The speeds required for interstellar travel in a human lifetime far exceed what current methods of spacecraft propulsion can provide. Even with a hypothetically perfectly efficient propulsion system, the kinetic energy corresponding to those speeds is enormous by today’s standards of energy production. Moreover, collisions by the spacecraft with cosmic dust and gas can produce very dangerous effects both to passengers and the spacecraft itself.

A number of strategies have been proposed to deal with these problems, ranging from giant arks that would carry entire societies and ecosystems, to microscopic space probes. Many different spacecraft propulsion systems have been proposed to give spacecraft the required speeds, including nuclear propulsion, beam-powered propulsion, and methods based on speculative physics.

For both manned and unmanned interstellar travel, considerable technological and economic challenges need to be met. Even the most optimistic views about interstellar travel see it as only being feasible decades from now—the more common view is that it is a century or more away. However, in spite of the challenges, if interstellar travel should ever be realized, then a wide range of scientific benefits can be expected.

Water on Mars

Water on Mars exists today almost entirely as ice, though it also exists in small quantities as vapour in the atmosphere[1] and occasionally as low-volume liquid brines in shallow Martian soil.[2][3] The only place where water ice is visible at the surface is at the north polar ice cap.[4] Abundant water ice is also present beneath the permanent carbon dioxide ice cap at the Martian south pole and in the shallow subsurface at more temperate latitudes. More than five million cubic kilometers of ice have been identified at or near the surface of modern Mars, enough to cover the whole planet to a depth of 35 metres (115 ft). Even more ice is likely to be locked away in the deep subsurface.